everything we look at is different. you could say, well, how many of those things that are different, physically, functionally, are chemically, really seem to be stronger, releasing to advantage the old brain? the answer is, none of them. alas, old is slower and less precise, less refined. old is slowly deteriorating. but there is good news in a moment, just wait for a moment. ok? [laughter] then we ask, how complex of the way we have to train the rat or how complex what we have to train the human to reverse these characteristics that define them as old? first, let me say something about being old. you could say if we're all deteriorating when we're older, why the heck do young people tolerate us? the answer is simple.